Camera flicker / optical ENF
Definition
The periodic brightness variation captured in video recorded under mains-powered fluorescent or LED lighting. The lighting modulates at 100 Hz or 120 Hz (twice the mains frequency), leaving an ENF signal encoded in the pixel intensity of video frames rather than in the audio channel.
Related terms
- Cross-correlation
- A mathematical sliding-window comparison that measures the similarity between two time series at every possible time offset. In ENF analysis it finds...
- Electric Network Frequency (ENF)
- The instantaneous frequency of the alternating-current mains supply, nominally 50 Hz in most of the world and 60 Hz in North America....
- ENF reference database
- A continuously maintained archive of grid frequency measurements recorded at high temporal resolution, used as the ground truth against which a recording's...
- ENF splice detection
- Using breaks or discontinuities in the ENF time series to identify edits, cuts, or inserted segments in a recording. A genuine unedited...
- Geographic grid disambiguation
- The process of determining which national or regional grid a recording's ENF trace came from, since the 50 Hz grids of continental...
Explained in
- Audio Authentication and the Electric Network Frequency MethodThe periodic brightness variation captured in video recorded under mains-powered fluorescent or LED lighting. The lighting modulates at 100 Hz or 120 Hz (twice...